Vol. XXJx] ENTOMOLOGICAL NEWS. 85 



ending in a sharp point. Lamellar hairs short, stout, simple, and 

 curved ; slightly surpassing the tips of lamellae. Pseudostigmatic 

 organs short, subcapitate, simple, and extending forward. Abdomen 

 longer than broad, sparsely clothed with rather short, strongly curv- 

 ed, simple setae. Pteromorphae large, attached to abdomen for over 

 one-half its length, and rounded below. Genital opening circular, 

 much smaller than anal opening and situated about one and one-half 

 times its diameter in front of the latter. Legs rather short ; last 

 pair not reaching the tip of abdomen; claws heterodactyle. Length, 

 0.54 mm. ; width, 0.39 mm. 



From the top of Mary's Peak ; under rotting logs and in 

 moss ; by the writer. Many specimens. This species belongs to 

 that group of Oribatellas that have the lamellae similar to 

 those of the genus Achiptcria Berlese. 



Family NOTHRIDAE. 



Liacarus bidentatus n. sp. (PI. Ill, fig. 10). 



A rather large, chestnut brown, shiny species. Lamellae extending 

 almost to tip of rostrum, their anterior third free, and each ending 

 in a small inner cusp. Lamellar hairs long, straight, apparently 

 simple ; each arising from tip of lamella outside of cusp, and extend- 

 ing far beyond the tip of cephalothorax. Pseudostigmatic organs 

 simple, swollen toward base, beyond which they are setiform. Ab- 

 domen almost as broad as long, hairless above. Genital opening 

 somewhat shield-shaped, very much smaller than anal opening, and 

 situated about twice its greatest diameter in front of the latter. Legs 

 long ; claws heterodactyle. Length, 0.91 mm. ; width, 0.62 mm. 



From top of Mary's Peak, Oregon ; under a rotting log, and 

 under a moist stone; by the writer. From Corvallis, Oregon; 

 under logs ; by the writer. From Cascade Mountains along 

 Santiam River; under a log; by the writer. The description 

 here given is based on the type specimen from Mary's Peak, 

 under a moist stone. The specimens from Corvallis are slightly 

 larger than the type. 



Liacarus robustus n. sp. (PI. Ill, tig. 11). 



A large, almost black, shiny species. Lamellae about four-fifths as 

 long as cephalothorax, with their anterior third free, and not ending 

 in cusps. Between the free ends of the lamellae is situated a cen- 

 tral mucro, which surpasses the tips of the lamellae, but does not 

 reach the tip of the rostrum. Lamellar hairs long, straight, minutely 

 and sparsely pectinate; each arises from the tip of lamella. Pseudo- 



